What Does P0416 Mean?
The PCM has detected a circuit malfunction in the secondary air injection switching valve B. This code is closely related to P0415 and indicates the electrical circuit for valve B is not responding correctly — the signal is outside the expected range. On V-configuration engines, this affects the bank 2 side of the AIR system. The driver will see the check engine light but should not notice driveability changes.
Common Causes
30%
Defective AIR switching valve B solenoid with intermittent open/short
30%
Damaged wiring harness with intermittent contact in the valve B circuit
20%
Corroded ground connection for the valve B circuit
12%
AIR relay B providing intermittent power to the valve
8%
PCM output driver degradation
Diagnostic Steps
1
Inspect the valve B connector for signs of heat damage, corrosion, or loose terminal fit. Perform a wiggle test on the connector while monitoring the valve command state on the scan tool.
2
Measure solenoid resistance at 20-40 ohms typical. If borderline or erratic, the coil is failing internally. Compare to valve A resistance if available for a baseline.
3
Check the ground circuit continuity from the valve B connector back to the PCM or chassis ground. Resistance should be below 0.5 ohms. Clean and re-torque the ground point if corroded.
4
Verify the relay B is delivering consistent 12V to the valve when commanded. Use a test light or multimeter to check for voltage drops across the relay contacts.
5
If all wiring checks pass, use a DVOM to monitor the PCM control signal while toggling the AIR system on/off. An inconsistent signal from the PCM side indicates a driver circuit issue.
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
The PCM has detected a circuit malfunction in the secondary air injection switching valve B. This code is closely related to P0415 and indicates the electrical circuit for valve B is not responding correctly — the signal is outside the expected range. On V-configuration engines, this affects the ban...
The most common cause of P0416 (Secondary Air Injection System Switching Valve B Circuit Malfunction) is: Defective AIR switching valve B solenoid with intermittent open/short
Typical repair costs for P0416 range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving. This is an emissions control system code with no impact on vehicle safety or driveability. The vehicle will not pass an emissions inspection with this code active.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0416 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emission Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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